#!/usr/bin/env python3

N = int(input().split()[0])
ans = "Yes" if N >= 30 else "No"
print(ans) N = int(input().split()[0]) N int(input().split()[0]) int input().split()[0] ().split() ().split () input split 0 ans = "Yes" if N >= 30 else "No" ans "Yes" if N >= 30 else "No" N >= 30 N 30 "Yes" "No" print(ans) print ans ans = "Yes" if N >= 30 else "No" "Yes" if N >= 30 else "No" ans N = int(input().split()[0]) int(input().split()[0]) N
#!/usr/bin/env python3

N = int(input().split()[0])
ans = "Yes" if N >= 30 else "No"
print(ans)
